Exactly how often Lyme disease strikes isn’t clear. The Centers for Disease Control and Prevention cites insurance records suggesting 476,000 people are treated for Lyme disease in the U.S. each year

This undated provided by the U.S. Centers for Disease Control and Prevention shows a blacklegged tick, also known as a deer tick, a carrier of Lyme disease. Justin Timberlake announced this week that he's been diagnosed with Lyme disease.